Craddock et al., U.S. Pat. No. 3,579,552 discloses the hydrocarboxylation of olefinically unsaturated compounds using rhodium catalysts and iodide promoters in which the reactant is dissolved in a compatible solvent. Acrylonitrile is listed as a suitable feedstock.
Burke, U.S. Pat. No. 4,788,334 discloses the hydrocarboxylation of olefinically unsaturated alkenes or esters using a rhodium catalyst, an iodide promoter, a solvent selected from the class consisting of methylene chloride, 1,2-dichloroethane, and C.sub.6 to C.sub.9 aromatic solvents, and an accelerator which is an acid having a pKa in the range of 4.2 to 5.2.